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Intermittent rotary motion

  1. Jun 16, 2009 #1
    I have intermittent rotary motion that I want to send to a continually running flywheel. The flywheel in mounted to one shaft, the intermittent rotary motion comes from a wheel or gear (driver) that is mounted to another shaft. Shafts are parallel. The flywheel is continually running but not rotating at a constant speed. Regardless of the flywheel speed, I want to be able to occasionally and at random give the flywheel a push via the driver when the driver gets a burst of random energy. When the driver does get a burst of energy, it will have this energy for only one revolution and it will then stop and wait for the next burst of energy. The driver wheel or gear can stop in a waiting location that is disengaged from the flywheel. Can someone direct me to the possible mechanisms that can perform this task?
  2. jcsd
  3. Jun 16, 2009 #2


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    Perhaps you can try some sort of clutch+fluid coupling as an automatic transmission. It seems like any direct mechanical coulpling wouldn't work as it would necessitate the two wheels to be moving at exactly the same speed when they engage otherwise there would be lots of jerking and losses.
  4. Jun 16, 2009 #3
    What if the OD of the flywheel had spur gear teeth, and the driver also has mating gear teeth but only about 3 or 4 teeth, the rest of the driver OD without teeth. The driver would stop immediately after delivering a push to the flywheel and the teeth of the driver would be just past and disengaged from the flywheel teeth. There, the driver would lay in waiting for the next burst of energy. Then it would rotate one full revolution, engage with the flywheel, give the push, and again stop just outside the reach of the gear teeth. Thus there is no tooth engagement whilst the flywheel is able to continue rotating. Does any such device exist? Would the gear teeth mesh or sometimes crash?
  5. Jun 16, 2009 #4


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    I suppose that a synchro system, as is used in a manual car transmission, might avoid crashes. This was actually the first thought that I had when reading the OP. An overrunning clutch (like an automotive Bendix) might be easier, though.
  6. Jun 16, 2009 #5
    This problem description really calls for an over running clutch in one form or another. Look at the possibility of a a sprag clutch for this application.
  7. Jun 16, 2009 #6
    The standard automobile starter with the starter (pinion) gear on a helical spline driving a flywheel might be a good statring point. You might have to drive a parallel geared up axle with the helical spline on it to get the speed necessary to engage the flywheel with the pinion gear. The nice thing about the pinion gear on the helical spline is that it releases automatically when the flywheel is going faster than the pinion gear.
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